Patients were examined on presentation and those requiring further treatment or observation were admitted to the short stay unit. Those with bronchiolitis were assessed for study eligibility within 2 hours of the initial physician assessment. Patients for whom consent was obtained underwent plain chest radiography and nasopharyngeal swabs were taken for RSV detection (RSV Respi-Strip, Coris Bioconcept, Gembloux, Belgium). Then a computer-generated list of random numbers was used by the enrolling physicians in consecutive order to identify a sealed envelope containing one of three codes identifying one of three different bags of 500 mL of sterilely-prepared blinded study solution, made fresh each morning by a pharmacist blinded to patient assignment.Patients received the study nebulization mixed with 1.5 ml of epinephrine in a double blinded fashion on enrollment and every 4 hours thereafter until they were ready for discharge.Additional nebulized epinephrine 5ml delivered the same way was administered with blinded study solution at a maximum frequency of every hour and additional treatment (e.g., supplementary oxygen, hydration) given at the discretion of the treating physician. Patients were withdrawn from the study if oxygen saturation within 30 min after nebulization fell below 85% on room air or clinical deterioration was determined to warrant transfer to the pediatric intensive care unit. Patients were discharged when the treating physician determined the patient did not need supplementary oxygen, was feeding adequately without intravenous fluids, and had minimal or absent wheezing, crackles, and chest retractions provided he/she had an oxygen saturation ≥ 94% and severity score < 4 on discharge.